Vast as was this progress from the days when at the siege of Acre the first real attention since the dark ages was given to the wounded by the Order of Teutonic Knights, there was still one serious imperfection that limited its sphere of usefulness--it did not apply to warfare on the seas. An effort had indeed been made in 1868 to extend the Red Cross rules to naval warfare, but it failed, and the wounded in conflicts on the sea continued to be left to the old provisions, which were necessarily inadequate and could not be exercised under the joint protection of the combatants. The virtue of the good Samaritan is a potent force, but to be fully effective on the field of battle it must be exercised under a common system established and maintained by the mutual consent of nations. It would, however, be a mistake to suppose that because the effort made in 1868 to extend these rules to sea warfare failed on account of their non-ratification, they were not sustained by public opinion. Many difficulties, especially those of a technical character, stood in the way; but public opinion was ever growing in their favor, and it eventually came to be regarded as an anomaly that while the care of the sick and wounded in land warfare had been regulated upon a common basis of international agreement, no similar provision existed for the care of the victims of naval combat. Without some such extension of the rules no adequate expression could be given to the growing humanity of the age. For these reasons it will be obvious that the next step necessary in the further development of the Red Cross work consisted of its extension to naval warfare. The Peace Conference subjected the Convention of 1864 and the additional rules of 1868 to a careful examination, considered at length the difficulties in the way, and finally adopted a new series of rules providing for an organized staff of physicians and nurses, with hospital ships and life-saving appliances, which shall, without interfering with operations, be henceforth employed in naval engagements and enjoy the protection of both combatants. The newly formulated rules, in conjunction with the previous ones relating to land warfare, are the practical embodiment of the growing feelings of humanity and mercy in the conduct of warfare which, commencing with the Peace of Westphalia, has been ever more and more effective in securing the evolution of a better usage. THE BRUSSELS RULES.--So, too, with reference to the rules governing the conduct of armies in the field the work of the conference represents a sound and healthy evolution.